[Scenario] battery graph uses relative path

Use a relative path to load the battery file
Draw battery graph if battery model exists and battery file exists
Draw power & comm graph if battery model or battery file doesn’t exist

Wrote or re-wrote unit tests (Y/N): N
Ran entire suite of unit tests successfully (Y/N): N
Verified bug fix with the described replication steps or verified the implementation meets the requirement cited (Y/N): N
Code coverage requirements satisfied (new code=80%, changed code=at least as high as existing) (Y/N): N
Code review date and attendees: Code review by pull request
Describe potential impact on other areas of the code: Scenario
Describe any test prerequisites for this fix (e.g., restart the database): NA
For bugs marked "Regression - Yes", describe the cause of the regression: 
Did you modify any pom.xml file? If yes, did you thoroughly document your changes and reasons? N